Rail sanding apparatus



P 1941- J. CANETTA RAIL SANDI'NG APPARATUS 8 Sheets-Sheet 1 Filed Dec.50, 1939 Sept. 16, 1 941. J.-CANETTA 2,256,289

RAIL SANDING APPARATUS ATTORNEY J. CANETTA RA-IL SANDING APPARATUS Sept.1 1941.

8 Sheets-Sheet 3 Filed Dec. 30, 1939 ATTORNEY Sept. 16, 1941. v J,CANETTA 2,256,289

RAIL SANDING APPARATUS Filed Dec. 50, 1939 s Sheets-Sheet 4 HUI 20INVENTOR JOHN CANETTA BY Wa n ATTORNEY Sept. 16, 1941. CANETTA 2,256,289

RAIL SANDING APPARATUS Filed Dec. 30, 1939 8 Sheets-Sheet 5 mm 0 Dmvzu'ro \JOHN GANETTA ATTORNEY Sept. 16, 1941. CANETTA 2,256,289 RAILSANDING APPARATUS Filed Dec. 50 1959 8 Sheets-Sheet} 1H 'INVENTOR we I l-JOHN CANETTA I WQ ATTORNEY Sept. 16, 1941;

J. CANETTA RAIL SANDING APPARATUS Filed Dec. 30, 1939 8 Sheets-Sheet 7 RNW NEW INVENTOR JOHN CANETTA BY ATTORNEY Sept. 16, 1941. J. CANETTA RAILSANDING APPARATUS Filed Dec. 50, 1939 a Sheets- Sheet a QEL INVENTORdOHN CANET TA ATTORNEY Patented Sept. 16, 1941 UNETED STATES PATENTOFFICE RAIL SANDING APPARATUS Application December 30, 1939, Serial No.311,721

52 Claims.

This invention relates to sanding apparatus and more particularly to thetype for use on railway vehicles for sanding the track rails.

In order to decelerate or stop the modern ultra high-speed railwaytrains in the relatively short distances required to meet operatingschedules and to insure the safety of the trains, it is necessary toemploy braking forces which are greater than ever before used.

The maximum degree of braking force which however may be employed on anyrailway vehicle or train is limited by the coefficient of adhesionbetween the vehicle wheels and rails since a greater degree of brakingforce is liable to cause sliding of the wheels which results not only inproducing flat spots on the wheels but also in an undesired lengtheningof the distance required to bring the train to a stop. Th coefficient ofadhesion of course usually depends upon the condition of the trackrails, that is, whether the track rails are dry or Wet, and is muchgreater when the track rails are dry than when wet, and in fact isusually so low when the rails are wet as to prevent the use of brakingforces such as required to provide a desired stop. To overcome thisdiificulty the use of sand on the track rails has been resorted to sinceit will provide a maximum and substantially uniform degree of adhesionregardless of the condition of the track rails.

Heretofore sanding of the rails has usually been effected automaticallywhen an emergency application of the brakes on a train has been effectedsince the degree of braking provided on a train at this time is usuallythe maximum obtainable. Manually controlled sanding has also beenprovided on most of these trains and while it has been available for useat any time, as during service brake applications, the primary purposethereof has been to provide sand on the rails for increasing thetraction of the locomotive unit during acceleration, but it is believedthat with the further development and us of ultra high speed trains,sanding of the track rails during service brake applications will becomeand be considered substantially as essential as during emergency brakapplications, in order to provide under all conditions of operation themost uniform and efficient brak control of the train.

Sanding arrangements heretofore employed on railway vehicles have beendesigned to provide a substantially constant rate of flow of sand forsanding purposes. The same amount of sand has thus been provided forsanding the track rails interferes with the signal systems employed onrailroads and is therefore undesirable.

One object of the invention is therefore to provide an improved sandingarrangement for railway vehicles which is operative to automatically aproportion the amount of sand supplied for sanding a track rail duringsanding operation substantially in accordance with the actualrequirements.

Still another object of the invention is to provide an improvedsandingarrangement such as above described which is operative in eiiecting bothservice and emergency brake applications and which may be entirelyautomatic in operation or which may be controlled manually by theoperator.

A still further object of the invention is to provide an'improvedsanding arrangement for a vehicle adapted at one time to provide sandfor sanding at a rate which varies substantially in proportion to thespeed of the vehicle and which may be operated at the will of theoperator to provide a certain maximum rate of sanding.

Another object of the invention is to provide an improved sandingarrangement for a railway 5 vehicle adapted to supply sand for sanding arail under said vehicle at a rate which varies substantially inproportion to the speed of the vehicle so as to avoid excessive use andwaste thereof.

40 Another object of the invention is to provide an improved sandingarrangement for use on railway vehicles adapted to provide sand forsanding a track rail in an amount substantially proportional to thespeedat which the vehicle is operating whereby substantially the same amountof sand will be provided on a unit length of track rail for all trainspeeds so as to minimize waste and excessive use of sand.

Other objects and advantages will be apparent from the following moredetailed description of the invention.

In the accompanying drawings; Fig. 1 is a diagrammatic view, partly insection and partly in outline, of a fluid pressure brake equipment for arailway vehicle and one form of the improved sanding arrangementassociated therewith; Fig. 2 is a sectional View taken on the line 2-2in Fig. 1; Figs. 3 to 5 are diagrammatic views mainly in outline of aportion of the apparatus shown in Fig. 1 and with which there isassociated various modified forms of the invention; Fig. 6 is adiagrammatic View somewhat similar to Fig. 1 disclosing anotherembodiment of the invention; Figs. 7, 8 and 9 are diagrammatic viewsmainly in outline of arrangements disclosing different modifications ofth structure shown in Fig. 6; Fig. 10 is a diagrammatic view mainly inoutline of an apparatus embodying another modification of the invention;Fig. 11 is a diagrammatic development view of a part of a valve deviceshown in Fig. 10; and Figs. 12 and13 are diagrammatic views of a portionof the apparatus shown in Fig. 10 and disclosing modified forms thereof.

Description of embodiment of invention shown in Fig. 1

The fluid pressure brake equipment shown in Fig. 1 for the purpose ofillustrating one application of the invention comprises an engineersautomatic brake valve device I, a main reservoir 2, a feed valve device3, an automatic brake controlling valve device such as a triple valvedevice 6, an auxiliary reservoir 5 and a brake cylinder device 6.

The engineers brake valve device I may be of the type disclosed inPatent No. 2,106,483 issued to Ellis E. Hewitt on January 25, 1938, andwhich is adapted to control the brakes on a vehicle or train through themedium of a brake pipe 'I.'

The brake valve device comprises a casing 8 to which the brake pipe 'Iis connected and an operating handle 8a adapted to be turned in ahorizontal plane for at one time reducing the pressure in the brake pipeI for effecting an application of the brakes on the vehicles of a trainand for at another time effecting :an increase in pressure in the brakepipe for effecting a release of the brakes on the vehicles of the train.

The operating handle 8a is preferably of the safety control type whichis also movable in a vertical plane, and is operative upon downwardmovement from the normal position shown, in all brake controllingpositions of the handle, to actuate a sanding bail 9 which is mounted topivot on a shaft I0 secured in. the brake valve casing. The sanding bail9 is arranged to engage the stem II of a sand valve I2 upon downwardmovement of the bail for unseating said valve against a spring I3; suchspring being provided for seating the valve I2 upon return of the handle8a to its normal position.

The sand valve I2 is contained in a chamber I4 which is connected by wayof a passage and pipe I5 to a fluid pressure supply pipe I6 which issupplied with fluid at a desired reduced pressure through the feed valvedevice 3 from the main reservoir 2. The Valve stem II is provided with afluted portion extending from the valve through a chamber H. The chamberI1 is connected by a passage I8 to a sand pipe I9. The valve I2 isoperative when unseated to supply the fluid under pressure from chamberI4 to chamber I7 and thence to the sand pipe I9, and when seated to cutoff such supply of fluid under pressure.

The triple valve device 4 may be of any suitable type adapted to respondto either a service or an emergency reduction in pressure in brake pipeI, eifected by operation of the brake valve device I, to supply fluidunder pressure from the auxiliary reservoir 5 through a pipe 69 to thebrake cylinder device 6 to effect either a service or an emergencyapplication of the brakes, respectively, on the vehicle. Upon anincrease in pressure in brake pipe I the triple valve device l isadapted to operate to recharge the auxiliary reservoir 5 from brake pipeI and to connect the brake cylinder 6 to the atmosphere for effecting arelease of the brakes on the vehicle. A further description of theconstruction and operation of the fluid pressure brake equipment on thevehicle is not deemed essential to a comprehensive understanding of theinvention.

According to the embodiment of the invention shown in Fig. 1, animproved sanding apparatus is provided which is so associated with thefluid pressure brake equipment above described as to operateautomatically when either a service or an emergency application of thebrakes is effected on the vehicle to supply sand for sanding the trackrails at a rate or to a degree which varies substantially according tothe speed at which the vehicle is operating, so as'to thereby ensuremost efl'icient braking of the vehicle but at the same time avoidexcessive use and waste of sand. For the purpose of simplicity only theapparatus necessary to provide sand for one rail is shown in thedrawings, it of course being understood that both rails of a railwaytrack are to be sanded and that such duplication of devices or partsthereof as required to accomplish this end fall within the scope of thepresent invention.

The improved sanding apparatus shown in Fig. 1 comprises a sandingdevice 20, a cleaning device 2'I therefor, a pneumatic switch device 22,a pneumatic cylinder device 23, a timing valve device 24, and ceratinother parts which will be later brought out.

The sanding device 211 is of conventional structure comprising a casing25 having therein a substantially horizontally extending sand carryingcavity 26. The cavity 26 is open at one end of the casing to an outletpipe 21 for conveying sand supplied thereto from cavity 26 to a trackrail 28 in front of a vehicle wheel 29. The opposite end of cavity 26 isopen to an upwardly extending sand supply passage 30, the upper end ofwhich connects to the bottom of a sand box 3| which is provided on thevehicle for carrying a supply of sand for sanding purposes and fromwhich sand is adapted to flow by gravity through the passage 38 into thecavity 26.

An air jet 32 is disposed in cavity 26 below passage 36 and is soarranged as to direct a blast of air supplied thereto in the directionof the outlet pipe 21 for thereby blowing sand deposited by gravity incavity 26 to said outlet pipe for sanding the track rail 28. The jet 32is connected to a pipe 33 through which fluid under pressure is adaptedto be supplied to the jet, and between said jet and pipe there isprovided a check valve 34 for preventing sand from cavity 25 enteringthe pipe 33.

The cleaning valve device 2I is also of usual construction comprising apiston 35 having at one side a chamber 36 connected to pipe 33 andhaving at the opposite side a chamber 31 open to the atmosphere througha passage 38 and containing a spring 39 actingon said piston for urgingsame to the position shown. The piston 35 is provided with a stem 40which extends through a suitable bore in the casing and which isprovided on its end with a double beat valve "aasaz'ee 4| disposed tooperate in a chamber 42. In the position which valve 41 is shown saidvalve is adapted to close communication between chamber 42 and a passage43. The valve 41 is adapted to be moved by piston 35, when fluid underpressure is supplied to chamber 36, from the position shown to anopposite position into engagement with a seat 44 forclosingcommunication between the fluid pressure supply pipe I6 and chamber d2.During movement of the valve 41 between its two seated positions alimited flow of fluid under pressure is adapted to occur from the fluidpressure supply pipe It through the chamber 42 to passage 43 as will beapparent.

The passage 53 is connected by a pipe 45 to a passage 48 in casing 25 ofthe sanding device 20. One end of passage 46 is connected to a cleaningpipe 41 the outer end of which is preferably closed and which isprovided with a plurality of spirally arranged outlet jets 48 throughwhich a blast of air is adapted to be directed into passage 36 forloosening and blowing sand out of said passage to the cavity 26. t theend of passage 46 connected to pipe 45 there is provided a port 49connecting said passage to cavity 26 and arranged to direct a blast ofair from said passage toward the outlet pipe 2'! for blowing sand out ofsaid pipe. By this arrangement, all of which is conventional, both theoutlet pipe 21 and sand supply passage 30 are adapted to be cleaned uponinitiating a sanding operation so as to insure prompt and intended flowof sand for sanding purposes, as will be later brought out.

According to the invention a slide valve is provided for controlling theflow capacity ofpassage 88 to supply sand by gravity from the sand box3! to cavity 28. This slide valve normally closes communication throughthe passage 30 so as thereby to cut off all supply of sand to cavity 26and is provided with a port 52 adapted 5 upon movement in the directionof the right hand, as viewed in Figs. 1 and 2 of the drawings, to opencommunication between the sand box 3| through passage (it to cavity 26.The

area of this communication and the capacity thereof to supply sand bygravity to cavity obviously depends upon the position of port 52 invalve 55 with respect to passage and increases upon move rent of thevalve toward the The slide valve 5! is provided at one end with a stem53 having a collar 54 adapted to engage the casing for defining theclosed position of the valve, as shown in the drawings. A spring 55 isprovided to act on collar 54 for moving the I valve 5! to its closedposition. An electro-magnet SS is provided for controlling the positionof the valve 5! and comprises an armature 57 operatively connected tothe opposite end of the valve and an operating coil 58 connected acrossE2. The wirestli and G2 are connected, resp'ec tively, to fixed contactfingers Stand 64 which are arranged to be electrically connected by amovable contact 65 associated with the pneumatic switch device 22.

The pneumatic switch device 22 comprises a casing containing a piston E6which is provided with a stem 61 carrying at its outer end the contact65. At one side of piston 66 there is provided a chamber 68 which isconnected by pipe 59 to the brake cylinder device 6. A spring it isprovided to act on the opposite face of piston t for operating saidpiston to draw the contact 15 out of circuit closing relation with thecontact fingers 63 and 64.

With the movable contact finger 65 in circuit closing relation withcontact fingers 63 and 64 it will be noted that the output of generatorBI is impressed on the operating coil 53 of the electrc-rnagnet 56 andwill effect movement of armature 5"! and thereby of the slide valve 5|in the direction of the right hand, as viewed in Figs. 1 and 2 againstthe opposing and measuring pressure of spring 55. The extent of thismovement of valve 5! is adapted to vary in accordancewith the output ofthe generator 5| as governed by the speed at which the vehicle isoperating and, as will be apparent, the area of port 52 in valve 53,which controls the rate at which sand will be supplied from the sand box3! to cavity 25 will therefore vary in accordance with the speed atwhich the vehicle is operating. These parts are so designed that whenthe vehicle is operating at a certain relatively high speed the slidevalve 55 will be positioned with the full area of port 52 in said valveeffective to supply sand to cavity 25. When the vehicle speed issubstantially zero the slide valve will be positioned to substantiallyout 01f all supply of sand to cavity 26, and for all intermediate speedsthe slide valve will be positioned so that the opening through port 52for supplying sand to cavity 26 will vary the rate of sand supply tocavity 26 in proportion to the different speeds.

The pneumatic cylinder device 23 comprises a casing containing a piston13 having at one side chamber 74 connected to pipe l9 and having at theopposite side a chamber 15 containing a spring 16 which acts on thepiston for urging the same to the position shown in the drawings. Thepiston F3 is provided with a stem 11 extending through chamber l5 and anopening in'the end of the casing into coaxial alignment with thearmature 51 of the electromagnet device 56. A release port 18 isprovided through piston l3 connecting chamber 14 to chamber 15 and thelatter chamber is open tothe atmosphere by way of a leakage groove 19provided through the casing along stem TI. With the piston stem H! inits normal position shown and with the armature 51 of the electro-magnetdevice 56 also .is connected to the brake cylinder pipe '69 and havingat the opposite side an operating stem 83 which projects into a chamber:84 connected to a pipe 85. A pair of oppositely seating valves 85 andEl are provided in a chamber 88 in coaxial alignment with the pistonstem 83. The

valve-86 is provided for controlling communication between chambers 88and 84 and has a fluted stem 89 arranged to be engaged by the pistonstem 83. .The valve 81 is arranged to control communication betweenchamber 88 and a chamber 90 and is provided with a fluted stem 9|extending into the latter chamber wherein a spring '92 is arranged toact on said stem for moving the valves 86 and 81 to their normalpositions, shown in the drawings.

The chamber 90 in the timing valve device is connected through an airstrainer device 9311 to the fluid pressure supply pipe l6. With thevalves 86 and 81 positioned as shown in the drawings, fluid underpressure supplied from the supply pipe |6 to chamber 99 is adapted toflow past valve 81 to chamber 88 and then through a pipe 93 to a sandingreservoir 94 for charging said reservoir with fluid under pressure. Thevalves 86 and 81 are adapted to be shifted to their opposite positionsby the piston 8| when fluid under pressure is supplied to chamber 82,and when thus positioned to close communication between chambers 90 and88 and open communication between chambers 88 and 84 to supply fluidfrom the sanding reservoir 94 to the pipe 85.

The pipe 85 is connected to one end of a double check valve device 91the other end of which is connected to pipe I9. The side outlet of thedouble check valve device 91 is connected to the pipe 33. The doublecheck valve device comprises a double check valve 96 arranged to operatein the usual manner to control communication between the pipe 33 and thepipes I9 and 85.

Operation of embodiment of invention shown in Fig. 1

Whenever either a service or an emergency application of the brakes onthe vehicle is effected by operation of the brake valve device I, fluidat the pressure supplied to the brake cylinder device 6 flows to pistonchamber 68 in the pneumatic switch device 22 and to piston chamber 82 inthe timing valve device 24.

The fluid pressure thus supplied to the switch device 22 actuates thepiston 66 to effect movement of the movable contact 65 into engagementwith the contact fingers 63 and 64 thereby connecting the coil 58 of theelectro-magnet device 56 in circuit with the generator 6| operated fromthe wheel 29. The output of the generator is thus impressed upon theoperating coil 58 of the electro-magnet device 56 and effects movementof the armature 51 and valve against the opposing force of spring 55 toa position dependent upon the speed at which the vehicle is operating atthe time. This movement of the valve 5| opens communication betweenthesand box 3| and cavity 26 in the sanding device through port 52 in thevalve to permit sand to flow by gravity from said sand box to saidcavity at a rate which is proportional to the speed of the vehicle.

At the same time as the pneumatic switch device 22 is thus operatedfluid pressure supplied to piston chamber 82 in the timing valve device24. actuates the piston 8| to unseat the valve 86 and to seat the valve'81. With the valve 86 unseated fluid under pressure flows from thesanding reservoir 94 to pipe 85 leading to one end of the double checkvalve 96. The fluid pressure in pipe 85 then shifts the double checkvalve 96 to the position for closing communication between pipe 33 andpipe I9 and for connecting the pipe 85 to the. pipe 33 whereupon fluidunder pressure flows from pipe to pipe 33 and then to jet 32 in thesanding device and also to piston chamber 36 in the cleaning valve 2|.

The fluid pressure thus supplied to piston chamber 36 actuates piston 35to effect movement of the double beat valve 4| from the position shownto its opposite position into engagement with the valve seat 44 andduring such movement a limited flow of fluid under pressure occurs fromthe fluid pressure supply pipe l6 to the passage 43. The fluid pressurethus supplied to passage 43 flows to passage 46 in the sanding device 20and then through jets 4B in the cleaning pipe 4'! to passage 30 forcleaning sand out of said passage and also from passage 46 through theport 49 to the sand pipe 21 for cleaning sand therefrom. This supply offluid to jets 48 and to the port 49 is in the form of a sudden blast ofshort duration to accomplish the cleaning action just described.

At the same time as the cleaning device 2| is operated, as justdescribed, fluid under pressure flows from pipe 33 past the check valve34 and through the jet 32 into cavity 26 of the sanding device 20 andthrough said cavity to the outlet pipe 21, and this stream of air isadapted to pick up and carry the sand supplied to said cavity throughthe sand valve 5| to the outlet pipe 21 through which said sand isadapted to be conveyed to the rail 28 ahead of the wheel 29 forincreasing the traction thereof.

The amount or quantity of sand thus supplied to the rail 28 is limited,as will be apparent, to the effective capacity of port 52 in valve 5| tosupply sand from the sand box 3| to the cavity 26 and will be greatestwhen the speed of the vehicle and therefore the output of the generator6| is sufficient to operate the electro-magnet device 56 to position thevalve 5| so as to render the full area of port 52 effective.

As the speed of the vehicle is reduced during braking, the output of thegenerator 6| is adapted to reduce accordingly and the correspondingreduction in force of the electro-magnet device 56 permits the spring 55to move the valve 5| toward the left hand to a position depending uponthe reduction in vehicle speed, and as will be apparent, the effectiveopening through port 52 in valve 5| will be reduced in proportion sothat the amount or quantity of sand supplied from the sand box 3| tocavity 26 will be correspondingly reduced. The supply of sand forsanding the track rail 28 will be thus varied in proportion to the speedof the vehicle wheel 29 and the parts are so designed and arranged thatthe amount or quantity of sand supplied for sanding rail 28 will providea substantially uniform degree of sanding regardless of the speed atwhich the vehicle is operating. Efficient braking of the vehicle isthereby ensured, and at the same time excessive use or waste of sandavoided.

The volume of the timing reservoir 94 is such as to provide for the flowof fluid under pressure through the jet 32 for a sufficient length oftime to supply sand through the supply pipe 21 to the rail 28 until thevehicle is brought to substantially a complete stop from the maximumspeed at which the vehicle might be operating at the time an applicationof brakes is initiated. The valve 5| and its control by the generator 6|are so arranged that at the time the vehicle speed reduces tosubstantially zero the spring 55 will have fully closed the valve 54against the opposing reduced force of the electro-magnet 56. By thisarrangement sand will not be supplied to the rail 28 and thus wastedwhen the vehicle is stopped and there is no use for sand.

When the fluid pressure is substantially completely vented from thesanding reservoir 94 and piston chamber 36 of the cleaning valve devicespring 39 acting on piston 35 returns the piston 35 to its normalposition shown thereby moving the valve 4! out of engagement with seatid and back to its normal position shown. During this movement of thedouble beat valve 4! a sudden but limited blast of fluid under pressurewill fiow from the fluid pressure supply pipe it to passage 43 and thento the sanding device 29 for efiecting cleaning thereof in the samemanner as occurred at the time the sanding operation was initiated. Thesanding device 2E3 is thereby conditioned to properly function upon asubsequent application of the brakes.

As is well known, it is customary to reduce the degree of brakeapplication on a vehicle or train as the speed reduces in order to avoidtoo rapid deceleration thereof or the possibility of sliding of wheels.As a result, at the time the vehicle comes to a substantial stop thedegree of pressure still acting in the brake cylinder device 6 will berelatively low. The spring El in the pneumatic switch device 22 is sodesigned as to move the piston 56 back to its initial position forthereby disengaging the contact 55 from the contact fingers 53 and 6whenever the pressure in the brake cylinder becomes reduced to therelatively low degree that might exist at the time the train is broughtto a full stop. By this arrangement the coil 58 of the electro-magnetdevice 55 is disconnected from the generator 5! at a time when nofurther sanding of the rail 28 is required so as to thereby avoidoverheating of said coil.

If when the brakes on the vehicle are applied the vehicle wheel 29should cease to turn on the rail 28 the output of the generator 6! andthe force of the electro-magnet device 56 will immediately reduce tosubstantially zero and as a consequence permit spring 55 to promptlyclose the valve 5! and thereby cut off the supply of sand to the rail 28in front of the wheel 29. This is very desirable in that it will avoidexcessive abrasion of the wheel and rail during the period of wheelsliding. If, subsequently, during the brake application the wheel 29starts turning on the rail 23 then current is again delivered by the 5generator 51 and operates the electro-magnet device 56 to again sand therail 28 for increasing the traction between said wheel and rail.

When the operator operates the brake valve device l to effect a releaseof the brakes on the vehicle subsequent to an application, fluid underpressure is vented from piston chamber 82 of the timing valvedevice 24along with that from the brake cylinder device 6 and when reducedsufliciently the spring 92 acting on the valve stem 9| unseats the valve87 and seats the valve 85. With the valve 8? thus open the sandreservoir 84 is again charged with fluid under pressure from the fluidpressure supply pipe it so as to be in condition for a subsequentsanding operation, such as just described.

It, at any time, the operator desires to supply sand to the rail 28, forincreasing the degree of adhesion between the rail and wheel 29 eitherduring braking or during acceleration of the vehicle, he may depress thebrake valve handle 8a. and thereby operate the bail 51 to move the valvestem H in a downwardly direction for unseating the sand valve l2. V fhenthe sand valve [2 is thus unseated, luid from the supply pipe i5 flowsto chamber l1 and then through passage I8 to pipe l9.

Fluid under pressure thus supplied to the pipe i9 flows to pistonchamber H3 in the pneumatic cylinder device 23 and therein acts onpiston 13 for effecting movement thereof in the direction of .the righthand against the opposing pressure of spring 15. ton stem l'i engagesthe armature 51 of the electro-magnet device 56 so that further movementof the piston 13 then acts through said armature to shift the slidevalve 5| against the pressure of spring to the position in which thefull effective area of port 52 is available to provide for a maximumflow of sand from the sand box 3! to cavity 26 in the sanding device 20.

At the same time as the pneumatic cylinder device 23 is thus operated,fluid under pressure supplied to pipe It! also flows to the double checkvalve device 51' and operates the check valve 96 to disconnect pipe frompipe 33 and to connect pipe 33 to pipe I!) so that fluid pressure thenflows from the pipe I!) to pipe 33 and then to the jet 32 in the sandingdevice and to the cleaning device 2!. The cleaning device then operatesin the same manner as hereinbefore described while the fluid pressuresupplied to the jet 32 blows the sand supplied through the valve 55 tocavity 26 out of said cavity to sand pipe 2'! and then to the rail 28.

The piston '13 may be operated to actuate the valve 5! as just describedwhen the electro-magnet 55 is effective during braking or at any othertime desired. This is however immaterial since whenever the piston 13 isoperated it provides sufficient force to overcome the spring 55 and movethe valve 5| to its full open position.

Whenever it is desired to terminate manual sanding of the track'rail 28,as just described, the operator permits the handle 8a of the brake valvedevice I to return to its normal position shown thereby relieving theunseating pressure on valve !2 which permits spring It to seat saidvalve and cut off the supply of fluid under pressure to pipe Iii. Thefluid pressure acting in piston chamber i i of the pneumatic cylinderdevice 23 is then dissipated through the release port it to chamber '15and then to the atmosphere through the leakage groove 19 whereuponspring 16 returns the piston 13 to its normal position shown. Spring 55acting on the slide valve 5| then returns said supply valve to itsnormal position so as to cut oil further flow of sand to the will thenoperate as heretofore described to effect cleaning of the sanding device20.

Since automatic sanding of the track rail 23 is insured whenever anapplication of the brakes on the vehicle is effected, regardless ofwhether such application is a service or an emergency application, theoperation of the brake valve handle 8a to manually effect sanding of therail during braking will seldom if ever be resorted to as will beapparent.

rails during acceleration and at any other time in case of emergency.

After slight movement, the pis- However, this manual sanding controlprovides for the usual sanding of the It is customary to make a standingtest of the brakes on a train before the train leaves a terminal, thatis, a test with the train not under motion, under which condition thereis obviously no need for sand on the rails. As will be apparent, nosanding of the rails will be effected with the present embodiment of theinvention under the condition just described, since the sanding isdependent upon movement of the vehicle.

Description of embodiment of invention shown in Fig. 3

In this embodiment of the invention means are provided for adjusting theposition of the sanding valve 5! in the sanding device 20 by fluid at apressure which is varied according to the speed at which the vehicle isoperating, instead of by the generator 6| and electro-magnet device 56shown in Fig. l and hereinbefore described. 7 As shown in Fig. 3, apneumatic cylinder device IOI is employed to cooperate with spring 55under all conditions of sanding to position the sanding valve 5!. Thecylinder device I! may be the same as the cylinder device 23 shown inFig. 1 except in the device IOI there is no spring provided at the lowpressure side of the piston I3 to oppose movement thereof upon thesupply of fluid under pressure to chamber I4 at the opposite side of thepiston. Extending from the slide valve for engagement by the pistonrodI1 is any suitable member such as armature 51 hereinbefore described.

The apparatus shown in Fig. 3 further differs 'from tha shown in Fig. 1in that it embodies a speed controlled device I02 for supplying fluid ata pressure which varies in accordance with the speed at which thevehicle is operating, and a cut-ofi valve device I03 for controlling thesupply of fluid from the device I02 to the pneumatic cylinder deviceIOI.

The device I02 comprises a casing having a stationary portion I04embodying a self-lapping valve mechanism including a supply valve I05and a release valve I06, and a rotary portion I01 embodying a centrifugedevice including weighted levers I08 pivoted intermediate their ends tosaid rotary portion III! of the casing and rotatable therewith. Therotary casing section I01 is adapted to be rotated according to thespeed of the vehicle as by an endless belt drive from an axle or otherelement driven according to the speed of the vehicle to a pulley I09coaxially secured to the casing I01. A rod or stem IIO extends into thestationary and rotary portions of the casing and is slidable withrespect thereto and the end of said rod in said rotary portion isengaged by the inner ends of levers I08. As the speed of the vehicleincreases the outer weighted ends of the levers I08 are adapted to moveoutwardly for urging the rod H0 in the direction of the stationaryportion I04 of the casing, while upon a decrease in vehicle speed theweighted ends of the levers are adapted to move inwardly to permitmovement of rod H0 in the opposite direction.

A movable abutment in the form of a piston I I I is slidably mounted inthe stationary casing section' I04 and is secured to the lower end ofthe stem I I0. At the upper side of the piston I I I is a chamber II2which is constantly open to the atmosphere through a port H13. At theopposite side of piston III is a chamber II4 which contains the releasevalve I06 and a light bias spring II5 which acts on the piston forurging same in the direction away from the release valve. The piston IIIis provided centrally with an exhaust passage II6 which is at all timesopen to chamber H2, and the valve I06 is arranged to controlcommunication between the chamber H4 and said passage.

The supply valve I05 is contained in a chamber II! and said valve andthe release valve I06 are connected together by a stem IIB which extendsloosely through a passage H9 connecting chambers III and II4. A springI20 in chamber II'I acts on the supply valve I05 for urging it to itsclosed position shown in the drawings. The chamber III is connected to apipe I2I through which fluid at the pressure carried in the supply pipeI6 is adapted at all times to be supplied to said chamber.

Briefly, the operation of the speed controlled valve device I02 is asfollows: Assuming that the vehicle is moving along the track the rotaryhousing I0! is caused to turn at a speed which is proportional to therate of movement of the vehicle. The action of centrifugal force on theweighted levers I08 causes said levers to move outwardly and exert aforce on stem I I0 for moving the piston I I I in a downwardly directioninto engagement with release valve I06 so as to close communicationbetween the chamber I I4 and release passage II6. As the action ofcentrifugal force on the weighted levers I08 continues to force thepiston III down, said piston acts through the release valve I06 and stemIIB to unseat the supply valve I05 whereupon fluid under pressure flowsfrom chamber I" through the passage II9 to chamber H4 and therein actson the piston III in opposition to the action of centrifugal force onsaid piston.

When the pressure of fluid in chamber H4 is thus increased sufficiently,acting in conjunction with the relatively light biasing pressure ofspring II5, to overcome the action of centrifugal force on piston II I,said piston is moved upwardly to permit the supply valve I05 to close toprevent further increase in pressure therein. Thus if the vehicle isoperating at a relatively high speed a relatively high fluid pressurewill be obtained in chamber II4, while in case the vehicle is operatingat a relatively low speed the pressure of fluid obtained in said chamberwill be at a correspondingly low degree. If the speed of the vehicleincreases an increase in centrifugal force will actuate the piston IIIto provide a proportionate increase in the pressure of fluid in chamberII4, as will be evident. In case the speed of the vehicle reduces, theaction of centrifugal force on piston III reduces a correspondingamount, which permits pressure of fluid in chamber I I 4 to move saidpiston in an upwardly direction and out of contact with the releasevalve I06. As a result, fluid under pressure is released from chamberII4 through the exhaust passage I I6. This release of fluid from chamberII4 reduces the pressure of fluid on piston II I and, as will be readilyapparent, when this pressure is reduced sufliciently the action ofcentrifugal force transmitted through stem IIO to said piston will movethe piston back into engagement with the release valve I06 forpreventing the further release of fluid under pressure from chamber II4. In this manner the pressure in chamber II4 will be maintainedproportional to the speed at which the vehicle is operating at alltimes.

The cut-off valve device I03 comprises a casing having a chamber I23which is at all times connected to chamber H4 in the speed controlleddevice I02 by way of a pipe I24. Whenever the vehicle is operating itwill therefore be apparent that chamber I23 will be charged with fluidat a pressure proportional to the speed of the vehicle.

The casing of the cut-01f valve device also has a chamber I25 open tochamber I23 through a bore I26 and also open to an outlet pipe I21. Avalve I28 is provided in chamber I23 for controlling communicationbetween chamber I25 and the bore I26. A spring I29 in chamber I23 actson valve i28 for normally urging it to its seat.

The valve 528 is connected to a stem I33 which projects from one face ofa piston I-3I through chamber I25. At the opposite side of piston I3ithere is provided a chamber I32 which is connected to a pipe I33 leadingto the brake cylinder pipe 59. A gasket I 34 is provided on the side ofpiston I3I adjacent chamber I25 for engagement by said piston.

The outlet pipe i21 is connected through a check valve device I38 to apipe I35'which leads to piston chamber 14 in the pneumatic cylinderdevice II. The pipe I9 through which sanding on the vehicle is adaptedto be manually controlled in the same manner as described in connectionwith the construction shown in Fig. l is also connected to the pipe I35through a check valve device I31.

Operation of embodiment of invention shown in Fig. 3

Whenever fluid under pressure is supplied to the brake cylinder devicefor applying the brakes on the vehicle, fluid also flows from the brakecylinder pipe 69 through pipe I33 to piston chamber 832 in the cut-offvalve device I03 and therein acts on the piston I3I to effect movementthereof into sealing engagement with the gasket I33. This operation ofthe piston I3I acts to unseat the valve I26 and thereby permit fluid atthe pressure supplied by the speed governor device I02 to chamber I23 toflow to chamber I25 and then through pipe I21, check valve device I38and pipe I35 to piston chamber 14 in the pneumatic cylinder device IBI.

The pressure of fluid thus obtained in chamber 14 acts on piston 13 toeffect movement thereof in the direction of the right hand against theopposing pressure of spring 55. The extent which the piston 13 is thusmoved depends upon the pressure of fluid supplied to chamber 1 3, saidfluid pressure and that of spring 55 cooperating to define a position ofthe sanding valve 5 I shown in Fig. 1, which corresponds to the pressureof fluid acting on the piston 13 and therefore to the speed at which thevehicle is operating. Sand is thus supplied from the sand box 3! to thesanding device 29 at a rate determined by the speed of the vehicle.

As the vehicle speed reduces the speed controlled device !82 acts toreduce the pressure of fluid in chamber H4 as above described and as aresult the pressure of fluid in chamber 14 acting on piston 13 in thepneumatic cylinder device It! correspondingly reduces through a smallleak port I35 which may be provided in pipe I35, it being noted thatwith this construction the speed controlled device acts to maintain thepressure of fluid in chamber M substantially equal to that in chamber IMagainst the continuous loss through this small leak port. As a result ofthe reduction to fluid pressure in chamber 1 3 spring 55 acts to urgethe sand valve 5| in the direction of the left hand to a position wherethe spring force is counterbalanced by the reduced pressure of fluid inchamber 14. The valve 5! thus assumes a new position corresponding tothe reduced speed at which the vehicle is operating and reduces theamount or quantity of sand supplied to the sanding device 20 inproportion to the reduction in speed. The spring 55 will thus continueto act as the pressure of fluid in chamber 14 continues to be reduced bythe speed controlled device I02 as the vehicle speed reduces to causefurther corresponding changes in the position of the sand valve 5| tothus reduce the rate at which sand is supplied from the sand box 3| tothe sanding device 26 in proportion to the reduction in speed of thevehicle. In other words, by varying the pressure of fluid supplied tochamber 14 for acting on piston 13 according to the changes in speed atwhich the vehicle operates the position of valve 5i will be varied byspring 55 to vary the rate at which sand is sup plied to the sandingdevice 2!] for sanding the track rail in proportion to the vehiclespeed, in the same manner as accomplished electrically with theapparatus shown in Fig. 1.

If, when the brakes on the vehicle are applied the wheel driving thespeed controlled device I02 should cease rotation and start sliding onthe rail, the action of centrifugal force on the weighted levers I58will promptly reduce to zero, as a result of which, the piston III willbe moved to the position shown by the pressure of fluid and that ofspring I I5 in chamber I I4. The supply of fluid to the cylinder deviceIii! will be thus cut off and the fluid pressure in chamber 14 thereofwill then promptly vent to the atmosphere through the leak port I 36. Asa result, spring 55 will operate the Valve 5| to cut off the supply ofsand for sanding the track rail. If subsequently the wheel for drivingthe speed. controlled device I32 should again start rotating, then fluidunder pressure will again be supplied to the cylinder device IfiI toefiect the supply of sand for sanding the rail at a rate proportional tothe rate of such rotation, as will be apparent. It will be noted thatduring sanding operation, the leak port I35 in pipe I35 provides aconstant leak of fluid under pressure from chamber I I4 in the speedcontrolled device I52 and another purpose for this is that it causes thepiston III to be constantly in operation during the sanding period so asto thereby remain in a very sensitive condition to accurately vary thepressure of fluid in chamber 1% of the cylinder device Ilil according tochanges in vehicle speed. The check valve I31 is provided to prevent theflow of fluid under pressure from pipe I35 as to pipe I9 leading to thebrake valve device I during automatic sanding operation just described.

Sand will continue to be supplied for sanding the track rail as abovedescribed as long as fluid is supplied to piston chamber 14 in thepneumatic cylinder device at a pressure suflicient to open the valve 5Ito any degree. The supply of sand may be terminated either by areduction in brake cylinder pressure in piston chamber I32 to arelatively low degree, such as five pounds, which may occur atsubstantially the time the vehicle comes to a stop and at which pressurethe valve I28 may be closed by spring I29, or said supply of sand may beterminated by the speed controlled device IIl2 at substantially the timethe vehicle comes to a stop when the force of the light bias spring II5becomes sufficient to overbalance the action of centrifugal force on thement connected to one contact finger I42.

weighted lever'arms I08 and move piston III away from the release valveI03. In either case the supply of sand to the rails will be terminatedby the time the vehicle stops and waste of sand will be avoided. Theprimary purpose of the cut-oil valve device I03 however is to preventthe supply of fluid under pressure to the pneumatic cylinder device IOIwhen the brakes on the vehicle are released,

Since the speed controlled device I02 acts to supply fluid underpressure for effecting sanding only when the vehicle is under motion itwill be noted that sand will not be supplied for sanding a track railwhen making a standing test of the brake system.

In case it is desired to manually effect sanding ofthe track rail thebrake valve device is operated to supply fluid under pressure to pipe I9through which it flows to the double check valve device 91 and thenceto'the sanding device for effecting operation thereof in the mannerbefore described. Fluid pressure supplied to pipe I9 also flows throughthe check valve device I31 to pipe I35 and thence to piston chamber 14in the pneumatic cylinder device WI. The pressure of fluid thus providedin chamber 14 acts on the piston I3 to efiect movement of the sand valve5| to its wide open position against the opposing pressure of spring 55.The maximum amount of sand for sanding of the track rails is thusobtainable upon operation of the brake valve device, as will beapparent. The check valve I38 acts during manual sanding, justdescribed, to prevent the flow of fluid under pressure from pipe I35 topipe I21.

Description of embodiment of invention shown in Fig. 4

In the arrangements shown in Figs. 1 and 3 of the drawings sanding ofthe track rail during braking is eifected automatically whenever eithera service or an emergency application of the brakes is effected on thevehicle. In Fig. 4 of the drawings is shown an arrangement whereby allsanding, including sanding according to speed, r

is directly under the control of the operator of the vehicle.

In the apparatus shown in Fig. 4, the sanding bail 9 is provided with anextension I40 on the lower face of which is fixed an electrical contactI adapted upon downward movement of the bail to engage two flexiblecontact fingers I42 prior to engagement of the bail with the sand valvestem II.

The wire 60, shown in Fig. 1 connected to the pneumatic switch device22, is in this embodi- In this embodiment the electromagnet device 56 isemployed to position the sand valve 5I and one terminal of the coil 58of said device is connected to wire 59 as in Fig. 1 while the otherterminal of said coil is connected to a wire I43 leading to the othercontact finger I42. It will thus be evident that the contact I40associated with the sand bail 9 and the contact fingers I42 constitutesa manually operative switch for controlling the energization anddeenergization of the electro-magnet device 56.

A supply magnet valve device I44 is provided for controlling the supplyof fluid under pressure to the sanding device 20 and to the cleaningdevice 2| in place of the timing valve device 24 shown in Fig. 1. Thismagnet valve device I44 comprises a magnet I45 connected across thewires I43 and 59 in parallel with the electromagnet device 56 and avalve I46 arranged to be opened upon energization of the magnet I45. Thevalve I45 is contained in a chamber I41 which is connected to the fluidpressure supply pipe I5 and in said chamber there is provided a springI48 acting on the valve for seating same upon deenergization of themagnet I45. The valve I46 is provided for controlling communica: tionbetween chamber I41 and a chamber I49 which is connected to a pipe I50leading to the double check valve device 91 in place of the pipe shownin Fig. 1.

Operation of embodiment of invention shown in Fig. 4

Whenever it is desired to effect sanding of the track rail 28 at a rateproportional to speed during braking, the operator depresses the brakevalve handle 8a. to a degree suflicient for operating the sanding bail 9to move the contact I40 into circuit closing relation with the contactfingers I42 for thereby connecting the electromagnet device 56 and alsothe magnet valve device I 44 in circuit with the generator 6| which issecured to rotate with the wheel of a vehicle as shown in Fig. 1 and ashereinbefore described. As a result the electro-magnet device 56 isenergized and operates in the same manner as hereinbefore described toposition the sanding valve 5I against the pressure of spring 55 so as tothereby supply sand from the sand box 3| to chamber 26 in the sandingdevice 20 at a rate depending upon the speed at which the vehicle isoperating.

At the same time as sand is thus supplied to the sanding device 20 theeenrgization of the magnet I44 unsea-ts valve I48 and supplied fluidunder pressure from pipe I6 to pipe I50 and then through the doublecheck valve device 91 to the sanding device 20 for blowing the sand topipe 21 for flow to the track rail.

The amount or quantity of sand supplied for sanding the rail will withthis embodiment of the invention vary in proportion to the speed of thevehicle as will be apparent and will continue so long as the operatormaintains the brake valve handle 8a in a position in which the contactI40 bridges the contact fingers I42 or until the vehicle is brought to asubstantial stop at which time the pneumatic switch device 22, shown inFig. 1, will operate to open the circuit through the electro-magnetdevice 56 and the magnet valve device I44 to cut oif the supply of sand.

In this embodiment of the invention the maximum amount of sand forsanding of the track rails may be obtained at any time by furtherdepression of the brake valve handle 8a and consequent operation of thebail 9 to unseat the sand valve I2 for supplying fluid under pressure topipe I 9, as will be apparent.

Description of embodiment of invention shown in Fig. 5

In this embodiment of the invention all sanding of the track rails isadapted to be controlled manually as in the embodiment just describedbut diiTers therefrom in that arrangements are provided for positioningthe sand supply valve 5I pneumatically in a manner'similar to thatdisclosed in Fig. 3 and above described.

As in Fig. 3, the speed controlled device I02 and cut-off valve deviceI03 are provided to control the supply of fluid at a pressure dependentupon the speed at which the vehicle is operating for controlling theoperation of the pneumatic cylinto the pneumatic cylinder device IOIfrom the speed controlled device I02 is however under the manual controlof the operators brake valve handle 8a as will now be described.

In the brake valve device there are provided two poppet valves I 39 andII which are arranged side by side and adapted to be simultaneouslyoperated by a sanding bail I 52 upon depression of the brake valvehandle 8a. The valve I39 is contained in a chamber I54 which isconnected through a passage I55 to the fluid pressure supply pipe I6 andis adapted to control communication between said chamber and a chamberI56 which is connected through a passage I51 and a pipe I58 leading tothe jet 32 in the sanding device 20 and to the cleaning device 2|. Thevalve I39 is provided with a stem I59 extending through chamber I56 andthrough the casing of the brake valve device into operating alignmentwith the sanding bail I52.

The valve I5I is contained in a chamber I60 which is connected by way ofpassage and pipe I6I to check valve device I30 and thence through pipeI21 to the cut-ofi valve device I03 and is provided for controllingcommunication between said chamber and a chamber I62 which is connectedthrough a passage and a pipe I63 to the pneumatic cylinder device IOI.The valve I5I is provided with a stem I64 which extends through chamberI62 and the casing of the brake valve device into operating alignmentwith the sanding bail I52, said stem and the stem I59 being arranged tobe engaged by the sanding bail I52 at substantially the same time upondownward movement thereof.

A spring I66 in chamber I54 acts on valve I39 for urging it to itsseated position shown, while a spring I61 in chamber I60 acts on thevalve I5I for urging it to its closed position also shown.

Disposed in a chamber I68 is a sand valve I69 adapted to perform thefunction of the sand valve I2 shown in Fig. 1. below and in coaxialrelation with the valve I39 and is provided with a stem I which extendsthrough a port connecting chambers I54 and I68. This stem is of suchlength that with both of the valves I39 and I69 seated there is slightclearance space between said stem and the valve I39 to provide forunseating of the valve I39 before engagement of valve I39 and said stem.Chamber I69 is connected through a passage III to the passage and pipeI63.

Operation of embodiment of invention shown in Fig. 5

Whenever the brakes on the vehicle are applied and it is desired toefiect sanding of the track rail at a rate depending upon the speed atwhich the vehicle is operating the operator depresses the handle 8asufficiently to actuate the sanding bail 52 to unseat the valves I39 andI 5I without however unseating the valve I69. The unseating of valve I5Ipermits fluid at a pressure supplied by the speed controlled device I02through the cut-off device I03 to chamber I60 to flow to chamber I62 andthen through passage and pipe I63 to the pneumatic cylinder device IIIIwhich is thereby operated to position the valve 5I to supply sand fromthe sand box 3I to the sanding device at a rate or in a quantity whichis proportional to the speed at which the vehicle is operating.

At the same time as sand is'thus supplied to Th valve I69 is arrangedthe sanding device 20 fluid under pressure from the supply pipe I6 flowspast the valve I39 to chamber I56 and then through passage I51 and pipeI58 to the sanding device 20 and cleaning device 2| for operating samein the same manner as hereinbefore described to blow the sand sup-1plied to said sanding device through pipe 21 to the track rail forsanding same.

The speed controlled valve device I92 operates as hereinbefore describedto reduce the pressure supplied for actuating the pneumatic cylinder device IOI as the speed of the vehicle reduces, and

- accordingly, the sand valve 5| is operated by the spring 55 to reducethe rate at which sand is supplied to the sand device 20 in proportionto the reduction in vehicle speed. The amount of sand supplied to thetrack rail 28 for sanding same will thus be varied such as to providefor a uniform degree of sanding regardless of the vehicle speed.

The operator may terminate sanding at will by removing pressure fromhandle 8a to permit closing of valves I39 and I5I in which case the leakport I36 provided, in this embodiment, in pipe I63 will promptlydissipate the fluid pressure from the pneumatic cylinder device I9I andpermit closure of valve 5I.

In case the operator maintains the valves I 39 and I5I open throughoutthe stop, the supply of sand will be terminated automatically either byclosure of the cut-oi? valve device I63 when the brake cylinder pressureis reduced to a relatively low degree or upon failure of the speedcontrolled device I02 to further supply fluid under pressure which willoccur at the time the vehicle comes to a substantial stop.

Whenever the operator desires to supply the maximum amount of sandto thetrack rail either during braking or acceleration he depresses the handle8a to a maximum degree and in so doing moves the valve I39 intoengagement with the valve stem I59 and unseats the valve I69. Fluid fromthe supply pipe I6 supplied to chamber I56 then flows past the valve I69to chamber I68 and then through passage III, and. pipe I63 to thepneumatic cylinder device .IOI wherein this pressure acts to fully openthe sand valve 5| against the opposing pressure of spring 55. Themaximum amount of sand is thus supplied to the sanding device 29 forsanding purposes, and fluid under pressure continues to be supplied inthis position of the brake valve handle past the valve I39 and throughpipe I53 to the sanding device 26 for blowing the sand suppliedthereto'to the track rail. In order to terminate this sanding of thetrack rail the operator relieves manual pressure on the brake valvehandle 8a which permits the various springs to seat the valves I69, I5I,and I69 as will be apparent.

By this arrangement the communication 30 connecting the sand box 3I tocavity 26 in the sanding device 20 may always be fully open to permit amaximum rate of flow of sand to said cavity but theamount of sand whichwill be blown from said cavity-to the-outlet pipe .-21 for sanding thetrack rail will vary according to the amount or pressure of fluidsupplied through the jet 32.

When the brakes on a vehicle are applied the degree of applicationdepends upon the pressure supplied to the brake cylinder-device. It iscustomary to provide amaximum degree of pressure in the brake cylinderat the time an application of the brakes is initiated and to graduallyreduce this pressure as the speed of the vehicle reduces, either byautomatic means which may be controlled by the speed of the vehicle, ormanually by the operation of a brake valve device. In either'casethebrake cylinder pressure is generally reduced according to the reductionin-vehicle speed and therefore is'usually' at all times during.brakingsubstantially a function of speed.

In the embodiment of the invention shown in Fig. 6 advantage is taken ofthis relation'between'brake cylinder pressure and vehicle speed to varythe amount or pressure of fluid supplied to the jet 32 in the sandingdevice 29'for blowing sand to the track rail whereby the amount of sandsupplied for sanding purposes will vary substantially as the vehiclespeed varies.

The brake equipment shown in Fig. 6 is, for the purpose of simplicity,adapted to be manua1ly.controlled,and let it be assumed-thatthe triplevalve device 4 is of the type adapted; to efiect a graduated release offluid from brake cylinder 6 upon the usual graduated release operationof the brake valve device I by the operator whereby the pressure .offluid in the brake cylinder device during deceleration of. the vehiclemay be maintained substantially .proportional to the speed at which thevehicle is running.

According to this embodiment of the invention the pressure existing inthe brake cylinder device 6, when the brakes on the vehicle are applied,is employed as apilot pressure for controlling a differential relayvalve device I which is adapted to operate to provide a correspondingpressure in a pipe I19 leading to the jet 32 in the sanding device 28and to the. cleaning device 2I. A timing valve device I'I4is providedfor control by the pressure of fluidinthe sanding reservoir 94 to limitthe length of time which the relay valve device I15 :will operate tosupply fluid under pressure for sanding purposes. The valve device 24 isprovided for con trolling the operation of the timing valve device I14according to the pressure existing .in the brake cylinder 6.

'The'relay valve device I151 comprises. a movable abutment in the formof a flexible diaphragm I11 having at one side a chamber I18connected toa pipe I19 and having at the opposite sidea chamber I81] connectedthrough a chamber'IBI to the pipe I16 leading'to the sanding device 20and cleaning device '2I. A sliding stem l82 is provided for movement bythe. diaphragm I11 upon deflection thereof in a downwardly directionwhile a spring 'lfidactson the stem for .moving it in the oppositedirection. A/rocking beam I84 in chamber ISI i pivotally connectedintermediate its ends to the stem I82.

The release valve I is connected to the beam Oneend of the beam I84 isarranged to control'the :op-

I84 for movementtherewith and isprovided for controlling communication-.betw.een chamber I8I and a release port-I81 which leads to theatmosphere. The supply valveIBS-is contained in a chamberI88 :which isconnected by a; pipe I89 to the fluid pressure supply pipe I6. A springI90 in chamber I88 is .providedfor urging the supply I86 to. its-closedposition.

The pipe I19 connects chamber 1 I18 totthe side outlet of. double checkvalve device. 91. One end of the double check valve.-91 is connectedto-pipe I9 .asinFig. 1 throughwhich fiuid-under-pressureisadapted to besupplied for sanding of the track. railat any time. Thelother endrof.the double check valve .deviceisconnected to.the pipe 'I9I which leadsto achamber I92 in the timing valve device. I14.

The timing valve device I14 comprises-a casing containing apistonI93havingatone side a chamber I94 which is connected to the timingreservoir pipel93. Inthe casingthere areprovided twooppositelyseatingvalves I95..and I96 having fluted stems which engage in chamber I92. Thevalve I95 is contained ina chamber I91 which is open-to the atmospherethrough a vent port I98. The piston I93 has astem I99 extending intochamber I91 forcontrollingthe valveI-95 and-the oppositely seating valve-L96. The valve I96 is contained in a .chamberJIll) which is connectedto the brake cylinder pipe 69. A spring 2M acts on;the valveI96.for.urging it toits seated position andforurgingthe valve I95 out ofengagement with its seat.

Operation of embodiment. ofinventz'on shown in Fig. '6

'When-the brakes on the vehicle are released and thebrake cylinder 6 isthereby void of'fluid under pressure, piston chambertllz'in' the valvedevice 24 is likewise vented'which permits spring 92110 unseat'the valve81-an'd"to seat the valve 86. This 'permits fluid under pressure .to'flow from'th'e flu-id pressure -supply'pipe I6 through chamber '90,past the valve -81 to "chamber 188 and then through-piped?" leading tothe timing reservoir =94 -and' to piston chamber'I94 inthe timing valvedevice I14. As a-result, the timing reservoir-94 is charged with'fluidatthe'pressure --supp1ied to the supply pipe I6-and this pressure-actingin chamber I94-of thetiming valvedevice on 1 piston I 93 shifts saidpiston to =a-nd 'holds same in theposition shown in which supplied tothe brake cylinder device then 'flows through-pipe- 69 to chamber 82 inthe-valve'device; 24. and alsoto chamber 209 in the timing-va-lve:device I19. Fluid" at brake cylinder pressure-thussuppliedtochamber 290 flows past the unseated valve I99 to .chamber I92 and thenthrough ,thedouble. check valve :device 91 to. diaphragm. chamber I 18in the relay valve "device I I15. The pressure of fluid .thussupplied to:cham- ;ber I 18in the relay valve-:devi'cexl 1.5 lactsio-n thediaphragm 1 I11 and .zdeflectssame. in .a down- :wardly-rdirection:wh-ich moves the stem 1'82 .and

thereby the fulcrum for beam I84 in the same direction.

Durin the initial downward movement of stem I82, as just described, oneend of the beam I84 fulcrums about a stop screw 283 provided in thecasing, due to which the opposite end of the beam acts to seat therelease valve I85. After the release valve is thus seated, furtherdownward movement of the stem I82 rocks the beam I84 about itsconnection with the release valve so that the opposite end of the beamengages the supply valve I86 and unseats same against spring I98. Fluidunder pressure supplied to chamber I86 then flows past the supply valveI35 to chambers I8! and I38 and from chamber I8I through pipe i16 to jet32 in the sanding device 28 and to the cleaning device 2| for effectingoperation thereof in the manner hereinbefore described.

It will be noted that there will be a continual venting of fluid underpressure from chamber I8I through the jet 32 in the sanding device 28,but the capacity of supply valve I86 to supply fluid under pressure tochamber I8I exceeds the venting capacity of the jet 32, as a result ofwhich the pressure of fluid increases in chamber I8I and in chamber I86at the lower side of the diaphragm I11 and when increased to a degreesubstantially equal to brake cylinder pressure acting in chamber I18,the spring I83 starts moving the stem I82 in an upwardly direction. Asthe stem I82 is thus operated the beam I84 is also operated to permitspring I98 to move the valve I86 toward its seat so as to reduce therate of supply of fluid under pressure to chamber I8I to a degree whichwill maintain the pressure of fluid in said chamber substantially equalto brake cylinder pressure acting in chamber I18. The pressure of fluidthus supplied to the jet 32 in the sanding device 28 will equal thatacting in the brake cylinder device 6 and will blow sand through thesanding device to the sand pipe 21 in an amount proportional to saidpressure and therefore proportional to brake cylinder pressure and thedegree of brake application.

When a reduction in pressure in brake cylinder 6 is effected tocompensate for a reduction in the speed of the vehicle said reductionbecomes effective in chamber I18 of the relay valve device I15. As aresult, the higher pressure in chamber I80 deflects the diaphragm I11 inan upwardly direction which permits spring I83 to elevate the stem I82permitting closure of the supply valve I86 and then opening of therelease valve I85. Unseating of the release valve permits the pressureof fluid acting in chambers IBI and I88 to reduce and when so reduced toa degree slightly less than the reduced brake cylinder pressure actingin the diaphragm chamber I18 the diaphragm I11 is again moved downwardlyby brake cylinder pressure and acts through the stem I82 to first seatthe release valve I85 and then unseat the supply valve I86 to an amountsufficient to maintain the pressure of fluid in the chamber I8I and inchamber I88 substantially equal to brake cylinder pressure in chamberI18.

In actual practice the release valve I85 may never open under thecondition just described since the required reduction in pressure inchamber I88 to effect readjustment of the supply valve iBS to thereduced brake cylinder pressure acting in chamber I18 may occur throughthe jet 32.

In either case the pressure of fiuid supplied through pipe I18 to thejet 32 in thesanding device 28 is reduced according to the reduction inbrake cylinder pressure so that a lower prese sure head is available toblow sand through the sanding device 20 to the outlet pipe 21 forsanding the rail. This results in less sand being supplied to the sandpipe 21 for sanding purposes, and assuming that the reduction inpressure in the brake cylinder device 6 corresponds to the reduction invehicle speed the amount of sand supplied for sanding is reduced inproportion.

When a further reduction of pressure in the brake cylinder 6 is effectedto compensate for a further reduction in vehicle speed, the relay valvedevice I15 will again operate to correspondingly reduce the pressure offluid supplied to the sanding device 28 and the amount of sand sup-pliedfor sanding the rail will be proportionately reduced, as will beapparent.

It will now be evident that if brake cylinder pressure is reduced inproportion to the reduction in vehicle speed in order to provide forinstance, a constant rate of deceleration of a vehicle, the sanding ofthe rails under a vehicle may be controlled by fluid at a pressure whichvaries in proportion to brake cylinder pressure and provide asubstantially uniform degree of rail sanding for all vehicle speeds. Inother words, the rate at which sand will be supplied or the quantity of'sand supplied will vary in proportion to the vehicle speed.

At the time the application of brakes is initiated the fluid at brakecylinder pressure supplied to piston chamber 82 in the valve device. 24moves the piston 8I in a downwardly direction to unseat the valve 85 andto seat the valve 81. This cuts off the supply'of fluid to the timingreservoir 94 and connects said reservoir past the valve86 to chamber 84which is open to the atmosphere through a choked passage 284." As aresult, the pressure of fluid in the timing reservoir 94 acting onpiston 93 in the timing valve device for holding the valve I96 openstarts to reduce to the atmosphere immediately when a certain low degreeof pressure, such as five pounds, is obtained in the brake cylinderdevice 6. .When the timing reservoir pressure becomes reduced to arelatively low degree the spring 20I in the timing valve device I'M actsto seat the valve I86 and unseat the valve I95 and during such movementmoves the piston I83 from the position shown in a downwardly direction.

The closing of valve I96 terminates the supply of fluid at brakecylinder pressure to the relay valve diaphragm chamber I18 while theopening of valve I95 vents said chamber to the atmosphere by way ofvalve I95 to chamber I91 and then through the vent port I88. When thisoccurs the pressure of fluid acting in chamber I88 of the relay valvedevice returns the diaphragm I11 to its normal position shown whichpermits spring I83 to elevate the stem E82 and thereby operate the beamI 84 to permit closing of the supply valve I86 and opening of therelease valve I85. This vents fluid under pressure from chambers I80 andI8! and from pipe I16 to the atmosphere by way of the vent port I81 thusterminating the supply of fluid under pressure to the jet 32 for sandingthe track rails.

The size of the timing reservoir 94 is however so related to the ventingcapacity of the choke 284 that the timing valve device I14 will notoperate to terminate sanding, as just described, until a vehicle hasbeen brought to a substantial stop fro-m a maXimum speed with the brakeson thevhicleapplied to a maximum degree, thereby insuring adequate sandfor braking during the most severe period of operation, but preventingundue loss of sand which might occur if the timing valve device Hdwerenot provided to limit the duration of sanding.

The only function-oi the valve device 24 in this embodiment is to chargethe timing reservoir 94 when the brakes on thevehicl are released andtodisconnect said reservoir from'the fluid pressure supply pipe IS and toconnect same-to the exhaust-port 284 during an application of the brakefor controllingthe period of operation of the timing valve device I74as-just described.

If atany timetheengineerdesires a maximumamount of sand applied'tc thetrack rail either during braking or acceleration he depresses the brake'valve handle-8a to unseat the sand valve I2 in the brake valve-devicevto supply fluid from the fluid' pressure supplypipe IE to pipe I9 in thesamemanner'as above described in connection withFig. 1. The 'flui'd'thussupplied to the pipe!!! flowsthrou'gh'the -double check valve 9! todiaphragm" chamber I18 in the relay valve device I and operates saiddevice to seat the release 'valve' I85 and to unseat'the supply valveI86 past whichfiuid at the pressure in the supply pipe [-5 "will'be.supplied'to pipe I16 leading to the jetr'32 in the sanding. device 20and 1 to the cleaning "device i'l'whi'ch then operate to provide amaximumflow of sand'to the sand pipe 21 for sanding the rail. Since. thepressure of fluid supplied by the brake valve device to diaphragmchamber'I'IB equals that which is obtainable past the supply valve [86in diaphragm chamber I88, the diaphragm I11 will maintain the supplyvalve I86. in a substantially wide open position to insure thatthepressure obtained at the jet 32 int-he sanding device 20 for sandpurposes will be substantially the same as in the supply pipe It as willbe evident.

Description of embodiment of invention shown in Fig. 7

If desired,'theduration ofthe sanding period by the apparatus shown inFig. 6 may be controll-ed'by movement of the vehicle instead ofvby thetiming valve device I14 and timing reservoir 9d, just described. Anapparatus embodying this modification is shown in Fig. '7 of thedrawings wherein the reference character 205' indicates anelectromagnetdevice which is adapted to be connected'in circuit with thegeneratoriil associated with the vehicle wheel '29 upon opera- 7 tion ofthe pneumatic switch device 22 when a certain low pressure is obtainedin the brake cylinder device 5, such as five pounds as hereinbeforedescribed in connection with the disclosure in Fig.1.

The electro-magnet device 205 comprises a magnet 266 having one terminalconnected to the wire and the other to the wire 59, shown in Fig. 1 ofthe drawings, andfurther comprises a pair of-oppositely seating valves25'! and 208. The valve 291 is contained in a chamber'ZflB connectedtothe brake cylinder pipeIES while the valve 238 is contained in a chamber2H1 which is open to'the atmosphere through a ventport 2! I. engage in achamber 2l'2 .which is open through pipe I9I' and the double check valvedevice'.91 to pipe I79 leading to therelay valve device I15. A spring 2I3 is provided in chamber ZGQ' for seating valve 201 *andfor unseatingvalvefifla.

The two valves have fluted stems which a tated Operation of embodimentof invention shown in Fig. 7

Inoperation,whenever. fluid under pressure is suppliedtoLthe brakecylinder device 6 to apply thebrakes on the vehicle'thepneumaticcylinder deviceiZ is operated to move the contact 65 intocircuit closing relation with the contact fingers 63 and so as toconnectthe magnet 285 into circuit with the generator 6i.

The magnet 206 is thereby energized and operates to seat valve (208 andunseat valve 201 whereupon fluid at brake cylinder pressure flowsfrom-pipe :69 through chamber 289 past valve 201 to chamber .2I2 andthenthrough pipe I9I, double check valve device 91 and pipe I19 to therelay-valve device H5. The relay valve device I then' operates ashereinbefore described to supply fluid at a corresponding pressure, tothe Sanding device 20 for effecting operation thereof to provide aproportionate flow of sand to the track rail for sanding same. Asthebrake cylinder pressure is reduced the relay valve device I15willoperate-to reduce the pressure of fluid supplied to the sanderdevice 20 and thus correspondingly reduce the amount of sand applied tothe track railfor sanding in the same manner as in the embodiment of theinvention shown in Fig. 6.

The supply of sandior sanding the track rail may be terminated in thisembodiment of the invention eitherby. the reduced output of generatorfilat the time the vehicle is substantially stopped or by-brake cylinderpressure reduced to a low degree at this time,--as-will now bedescribed.

When the vehicle becomes substantially stopped, the output of thegenerator 6| will be insuflicient to maintain the magnet 286 energized,asa result of which spring 2I3 will seat valve 201 and unseat valve 208.The supply of fluid from the brake cylinder device to therelay valvedevice I15 will-be thus cut off and diaphragm chamber I18 in said'relayvalve device vented to the atmosphere past the valve 208 and through thevent passage 2| I. The relay valve device will then operate ashereinbefore described to out off the supply of fluid under pressuretothe sanding device 20 to thus terminate sanding of the rail. In case thepressure of fluid in thebrake-cylinder device 6 should'become reducedsufficiently low before the output of generatorfii becomes reducedsufllciently to terminate sanding, then the pneumatic switch device 22will operate to'open the circuit through the magnet 2% and terminatesanding. The primary purpose of the pneumatic switch device 22 ishowever-to open the circuit through magnet 265 at all times exceptduring braking.

If, in this embodiment, the-vehicle wheel to which the generator BI isconnected should cease to rotate at any time during braking the magnetvalve device 205 will operate to out off the supplyof fluid underpressure to the'relay valve device I15 which in turn will cut off thesupply of fluid under pressure forblowing sand to the track rails; so asto thus prevent excessive abrading of the vehicle wheel during suchsliding. In case the vehicle wheel should subsequently startrotating-again, sanding ofthe-rail will again occur, as will beapparent.

Description ofembodiment of invention shown in Fig. 8

Inlthe embodiment of the invention shown in Figifi'the amount of sandsupplied for sanding

